77970391 has 4 divisors (see below), whose sum is σ = 81360432. Its totient is φ = 74580352.

The previous prime is 77970377. The next prime is 77970401. The reversal of 77970391 is 19307977.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 77970391 - 2¹⁷ = 77839319 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77970311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1694986 + ... + 1695031.

It is an arithmetic number, because the mean of its divisors is an integer number (20340108).

Almost surely, 2^77970391 is an apocalyptic number.

77970391 is a deficient number, since it is larger than the sum of its proper divisors (3390041).

77970391 is a wasteful number, since it uses less digits than its factorization.

77970391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3390040.

The product of its (nonzero) digits is 83349, while the sum is 43.

The square root of 77970391 is about 8830.0844276824. The cubic root of 77970391 is about 427.2117975877.

The spelling of 77970391 in words is "seventy-seven million, nine hundred seventy thousand, three hundred ninety-one".